>>96173017
To my knowledge there's no indication that Gygax ever attempted patenting the game, he would know it'd be moot since he was in the business prior to that and patents are a very pricy process. Trademarking yes, and telling magazines using the name to stop doing so or offering a licensing deal if they were doing good work like JG.
TSR didn't become lawsuit happy until after he had been ousted from the company, pretty much all that went beyond regular trademark C&Ds only started in 1984 with Mayfair.